An attempt to identify source areas of clastic deposits from selected caves of the Prokletije Mountains (Montenegro): a mineralogical and U-series geochemistry approach

Abstract

The Prokletije Mountains/Albanian Alps are the highest part of the Dinaric Mountains. Paradoxically, these mountains and their cave areas remain among the most enigmatic in Europe, having only recently become subjects of scientific research and cave exploration. This paper focuses on the Kolata and Greben massifs, where the highest, and thus the oldest, cave systems are located. Through the analysis of heavy mineral composition, the apatite-tourmaline index, and cluster analysis for mineralogical composition and uranium isotopic data, it becomes possible to identify the source areas for the cave clastic deposits. It also allow to distinguish multiple paleoflow directions, each corresponding to different stages of cave development. The older paleoflow was probably from south to north, whereas the younger one is inferred to have flown from east to west. The change in the paleodirection of sediment transportation was probably caused by Neogene tectonic movements. In the later period, because of the subsequent uplift of the Prokletije Mts. and their fragmentation into individual massifs, the transport to the caves was local and related to deglaciations. The deposition of the speleothem from the oldest caves of the Prokletije Mts. took place in the periods c. 381 and 308 ka (MIS 11 and MIS 9), which suggests that these levels had already passed from the phreatic to the vadose stage. Considering the morphology of the caves studied, we believe that these caves may have begun to form at least in the Middle Pleistocene. There are two generations of younger speleothems first at 163 ± 4 ka (MIS 6) and second from 92 ± 2 to 39.4 ± 2 ka (Weichselian age).